Advection fog

The "Misty Mountains" in Lord of the Rings, filmed in NZ, was the Paparoa Range, north of Greymouth. Advection fog rolls in real time over the mountains and descends for a short way on the seaward side. The bitterly cold land breeze that is responsible, blows down the main street of the town every winter morning. It is known locally as the "Greymouth Barber".

Video: Jacobs